Not enough info Joe.
That is an exterior pump ?
If so? then the feed from tank to it may be airlocked if it is fed from top of the tank, or possibly one of the non return valves is stuck open. The pump requires water pressure to shut off so sounds like it isn’t being fed this causing it to run continuously.
Is there air at the taps when open?.
A few tests on the pump from a known feed would definitely rule the pump serviceable or not.